PostgreSQL-建立资料库动态表 [英] Postgresql - Create Database & Table dynamically

问题描述

此代码不起作用。有人可以指导我在哪里找到使用C＃快速创建Postgresql数据库和表的示例吗？

This code is not working. Can anyone direct me where I can find examples of creating a Postgresql database and table on the fly with C#?

     const string connStr = "Server=localhost;Port=5432;
                          User Id=postgres;Password=enter;Database=postgres";

        var m_conn = new NpgsqlConnection(connStr);

        // creating a database in Postgresql
        m_createdb_cmd = new NpgsqlCommand("CREATE DATABASE IF NOT EXISTS  \"testDb\" " +
                                       "WITH OWNER = \"postgres\" " +
                                       "ENCODING = 'UTF8' " +
                                       "CONNECTION LIMIT = -1;", m_conn);

        // creating a table in Postgresql
        m_createtbl_cmd = new NpgsqlCommand(
            "CREATE TABLE MyTable(CompanyName VARCHAR(150))";

        m_conn.Open();
        m_createdb_cmd.ExecuteNonQuery();
        m_createtbl_cmd.Connection = m_conn;
        m_conn.Close();

数据库已创建，但在创建表时却出现静默失败。

The db is created but I get a silent fail on creating the table.

推荐答案

我会这样做：

string connStr = "Server=localhost;Port=5432;User Id=postgres;Password=enter;";
var m_conn = new NpgsqlConnection(connStr);
var m_createdb_cmd = new NpgsqlCommand(@"
    CREATE DATABASE IF NOT EXISTS testDb
    WITH OWNER = postgres
    ENCODING = 'UTF8'
    CONNECTION LIMIT = -1;
    ", m_conn);
m_conn.Open();
m_createdb_cmd.ExecuteNonQuery();
m_conn.Close();

connStr = "Server=localhost;Port=5432;User Id=postgres;Password=enter;Database=testDb";
m_conn = new NpgsqlConnection(connStr);
m_createtbl_cmd = new NpgsqlCommand(
   "CREATE TABLE table1(ID CHAR(256) CONSTRAINT id PRIMARY KEY, Title CHAR)"
   , m_conn);
m_conn.Open();
m_createtbl_cmd.ExecuteNonQuery();
m_conn.Close();

不建议在此处使用 var 。我之所以使用它，是因为我不知道返回的类型是什么，但是您应该这样做。

The use of var here is not recommended. I used it as I don't know what are the returned types but you should.

注意使用原始字符串（ @ ）。

Notice the use of a raw string (@). It makes string building simple.

请勿在Postgresql中使用双引号括起来的标识符，除非该标识符是非法的。它将使您的生活更加艰难。

Do not use identifiers surrounded by double quotes in Postgresql unless the identifier is otherwise illegal. It will make you life much harder.

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